// Accepts a URL and a callback function to run.
function requestCrossDomain( site, callback ) {
// If no URL was passed, exit.
if ( !site ) {
alert('No site was passed.');
return false;
}
// Take the provided URL, and add it to a YQL query. Make sure you encode it!
var yql = 'http://query.yahooapis.com/v1/public/yql?q=' + encodeURIComponent('select * from html where url="' + site + '"') + '&format=xml&callback=cbFunc';
// Request that YSQL string, and run a callback function.
// Pass a defined function to prevent cache-busting.
$.getJSON( yql, cbFunc );
function cbFunc(data) {
// If we have something to work with...
if ( data.results[0] ) {
// Strip out all script tags, for security reasons.
// BE VERY CAREFUL. This helps, but we should do more.
data = data.results[0].replace(/<script[^>]*>[\s\S]*?<\/script>/gi, '');
// If the user passed a callback, and it
// is a function, call it, and send through the data var.
if ( typeof callback === 'function') {
callback(data);
}
}
// Else, maybe we requested a site that doesn't exist, and nothing returned.
else throw new Error('Nothing returned from getJSON.');
}
}

(I'm relatively new to scripting and Ajax, so I apologise in advance if I do anything stupid.)